Version Vertx 4.3.4, JDBCClient
Questions Our Oracle-database is setup in the local-timezone "Europe/Vienna" and returns the local-time over JDBC. But within the convertion of the VertX-JDBC the time markt in any case to UTC.
If you do a
pool.preparedQuery("select SESSIONTIMEZONE as sessionTimeZone, sysdate as dateValue, to_char(sysdate,'yyyy-dd-mm hh24:mi:ss') localTime from dual")
The output will be:
"sessionTimeZone":"Europe/Vienna", "dateValue":"2022-10-17T10:06:45Z", "localTime":"2022-17-10 10:06:45"
I assume it is related to this code-part (JDBCDecoderImpl.java, Line 188), where the returned timestamp is set hard-coded to UTC:
if (descriptor.jdbcType() == JDBCType.TIMESTAMP || descriptor.jdbcType() == JDBCType.TIMESTAMP_WITH_TIMEZONE) {
return LocalDateTime.parse(value.toString(), DateTimeFormatter.ISO_LOCAL_DATE_TIME).atOffset(ZoneOffset.UTC);
}
The oracle-jdbc-driver always return the timestamp in the timezone the database is setup. There is no possibility as it is at MySQL, where the timezone could be defined.
Is there a way to workaround this conversion?
This is a known issue from JDBC with Oracle Databases. In order to correctly set the timezone (without requiring any code changes) you can issue the following statement at start of each connection:
ALTER SESSION SET TIME_ZONE = 'UTC'
This will allow you to set the timezone for the session which should match the application. In this case, UTC.
There are other options too. For example if you can modify the database you can set the database timezone at creation time:
CREATE DATABASE myDB
...
SET TIME_ZONE='UTC';
Or modify it after creation:
ALTER DATABASE myExistingDB
...
SET TIME_ZONE='UTC';
If you don't want/can alter the database and want to keep using the vert.x client without managing the connection yourself, in other words, keep using 1 shot queries, you can specify at the query level the timezone too:
SELECT
FROM_TZ(TIMESTAMP '2030-01-01 12:30:35', '-04:00')
AT TIME ZONE '+12:00'
FROM DUAL;